members are loaded--they'll see resets, score finalization, etc. It
also results in smaller code, due to a g++ bug that causes constructors
to be emitted several times.
havn't finished checking it out yet (eg. write check). This improves responsiveness:
a slow card will indicate that we see the card immediately, and it helps
diagnostics since we can easily tell if the machine sees a card. Allow re-
establishing a memory card removed after finalization, as long as it has the
same serial number.